Apparatus and method for detecting biological information

ABSTRACT

Provided are apparatuses and methods for detecting biological information. An apparatus for detecting biological information may include a biological signal measurement unit having at least two light emission elements having different light emission angles. The at least two light emission elements may include different types of light sources. The at least two light emission elements may include multiple light sources of the same type, and in this case, an optical element configured to adjust a light emission angle of one of the light sources may be provided. The apparatus for detecting biological information may include a biological signal measurement unit including a light emitting unit having variable light emission angle. The apparatus for detecting biological information may further include a data processor configured to extract and analyze biological information of a subject from data measured by the biological signal measurement unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2015-0095198, filed on Jul. 3, 2015, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND

1. Field

Apparatuses, systems, and methods consistent with exemplary embodimentsrelate detecting biological information.

2. Description of the Related Art

As medical science has progressed and average life expectancy hasincreased, an interest in health care has increased. Also, interest inmedical equipment/devices has increased to extend not only to varioustypes of medical equipment used in hospitals or health examinationfacilities, but also to middle- or small-sized types of medicalequipment provided for use in public facilities and compact medicalequipment and health-care apparatuses that may be kept at home orcarried by individuals.

Biological information of a subject may be detected by an invasivemethod or a non-invasive method. Using a non-invasive method, biologicalinformation may be detected in a relatively simple manner withoutcausing pain to a subject. However, when biological information isdetected using a non-invasive method, it may be difficult to guaranteethe accuracy and precision of the detection results.

SUMMARY

One or more exemplary embodiments may provide apparatuses, systems andmethods for detecting biological information, whereby biologicalinformation of a subject may be easily detected.

One or more exemplary embodiments may provide apparatuses, systems andmethods for detecting biological information, whereby the detectionaccuracy and reliability may be improved.

Additional exemplary aspects and advantages will be set forth in part inthe description which follows and, in part, will be apparent from thedescription, or may be learned by practice of the presented exemplaryembodiments.

According to an aspect of an exemplary embodiment, an apparatus fordetecting biological information includes a biological signalmeasurement unit including a light emission portion and a photodetector,the light emission portion including at least two light emissionelements having light emission angles of different sizes, thephotodetector being configured to detect light generated by the lightemission portion and modulated by a subject, and a data processorconfigured to extract and analyze biological information of the subjectfrom data measured by the biological signal measurement unit.

The at least two light emission elements may include a first lightemission element and a second light emission element, the first lightemission element may include a first light source, the second lightemission element may include a second light source of a different typewith respect to the first light source, and the first light source andthe second light source may have different light emission angles.

A light emission angle of one of the first light source and the secondlight source may range from about 0° to about 90°, and a light emissionangle of the other may range from about 80° to about 180°.

One of the first light source and the second light source may be a laserdiode (LD), and the other may be a light emitting diode (LED).

The at least two light emission elements may include a first lightemission element and a second light emission element, the first lightemission element may include a first light source, the second lightemission element may include a second light source of a same type withrespect to the first light source, and one of the first light emissionelement and the second light emission element may further include anoptical element configured to adjust a light emission angle of lightgenerated by the light source thereof.

The optical element may include at least one of a lens, an opticalwaveguide, a slit, a concave mirror, and a convex mirror.

One of the first light emission element and the second light emissionelement may include the optical element and the other of the first lightemission element and the second light emission element may not includethe optical element.

The first light emission element may include a first optical elementcorresponding to the optical element, and the second light emissionelement may include a second optical element different from the firstoptical element.

The at least two light emission elements may include a first lightemission element and a second light emission elements, a light emissionangle of one of the first and second light emission elements may rangefrom about 0° to about 90°, and a light emission angle of the other ofthe first and second light emission elements may range from about 80° toabout 180°.

The data processor may be configured to select a signal having arelatively high signal-to-noise ratio (SNR) from among a plurality ofdetected signals measured by the at least two light emission elementsand to extract and analyze biological information of the subject usingthe selected signal.

The at least two light emission elements may include a first lightemission element and a second light emission element, and thephotodetector may include at least one light receiving device configuredto receive both of an optical signal based on light emitted by the firstlight emission element and an optical signal based on light emitted bythe second light emission element.

The at least two light emission elements may include a first lightemission element and a second light emission element, the photodetectormay include at least one first light receiving device and at least onesecond light receiving device, and the first light receiving device maybe configured to selectively receive an optical signal generated bylight output by the first light emission element, and the second lightreceiving device is configured to selectively receive an optical signalgenerated by light output by the second light emission element.

The first light emission element may generate light of a firstwavelength range, and the second light emission element may generatelight of a second wavelength range different from the first wavelengthrange, and the first light receiving device may be configured to receivean optical signal corresponding to the first wavelength range, and thesecond light receiving device is configured to receive an optical signalcorresponding to the second wavelength range.

The photodetector may include a plurality of light receiving devices,and the plurality of light receiving devices may be disposed in an arraysurrounding at least a part of the light emission portion.

The photodetector may include a plurality of device regions around thelight emission portion, and each of the device regions may include aplurality of light receiving devices and the plurality of lightreceiving devices may be configured to receive light of differentwavelength ranges.

The light emission portion may include a plurality of first lightemission elements having a first light emission angle and a plurality ofsecond light emission elements having a second light emission angle, andthe plurality of first light emission elements and the plurality ofsecond light emission elements may be alternately arranged in atwo-dimensional array.

The light emission portion and the photodetector corresponding to thelight emission portion may constitute one sub-unit, and the biologicalsignal measurement unit may comprise an array of a repeating arrangementof a plurality of the sub-units.

The biological signal measurement unit may be configured to measure aneffective measurement surface of the subject via a non-contact method.

The biological signal measurement unit may further include at least onespacer protruding toward one side of the biological signal measurementunit, in which the at least one spacer separates the light emissionportion and photodetector from a surface of the subject.

The biological signal measurement unit may be configured to measure asurface pulse wave and/or photoplethysmogram (PPG) of the subject.

Biological information detected by the apparatus for detectingbiological information may include at least one of a blood pressure, aheart rate, a blood oxygen saturation, a blood vessel elasticity, ablood flow rate, and arterial stiffness.

The apparatus may further include a light source driver connected to thebiological signal measurement unit, and a signal converter connectedbetween the biological signal measurement unit and the data processor.

The apparatus may further include a processor, in which the processorincludes the data processor and a controller.

At least a part of the apparatus for detecting biological informationmay constitute at least a part of a portable device or a wearabledevice.

According to an aspect of another exemplary embodiment, an apparatus fordetecting biological information includes a biological signalmeasurement unit including a light emission portion and a photodetector,the light emission portion including at least one light emitting unithaving a variable light emission angle, the at least one light emittingunit including a light source and a light emission angle control elementconfigured to control a light emission angle of the light source, thephotodetector detecting light generated by the light emission portionand modulated by a subject, and a data processor configured to extractand analyze biological information of the subject from data measured bythe biological signal measurement unit.

The light emission angle control element may include a variable focusinglens.

The light emission angle control element may include one of an autofocusing module (AFM) comprising a voice coil motor (VCM), a liquid lensusing comprising electrowetting unit, and a variable focal lengthmicrolens comprising liquid crystal.

A light emission angle of the light emitting unit may be controlledaccording to a distance between the light source and the subject.

The apparatus may further include a distance measuring sensor configuredto measure a distance between the light source and the subject.

The data processor may be configured to select a signal having arelatively high signal-to-noise ratio (SNR) from among a plurality ofdetected signals measured while changing a light emission angle of thelight emitting unit.

The photodetector may include a plurality of light receiving devices,and the plurality of light receiving devices may be disposed in an arraysurrounding at least a part of the light emission portion.

The light emission portion may include a plurality of the light emittingunits, and/or the light emission portion may further include at leastone light emission element having a fixed light emission angle.

The biological signal measurement unit may be configured to measure asurface pulse wave and/or photoplethysmogram (PPG) of the subject.

Biological information detected by the apparatus for detectingbiological information may include at least one of a blood pressure, aheart rate, a blood oxygen saturation, a blood vessel elasticity, ablood flow rate, and arterial stiffness.

According to an aspect of another exemplary embodiment, a method ofdetecting biological information includes irradiating a measurement areaof a subject with incident light from at least two light emissionelements having different light emission angles, generating a pluralityof signals from light output by the at least two light emission elementsand modulated by the measurement area, and selecting a signal having arelatively high signal-to-noise ratio (SNR) from among a plurality ofgenerated signals, and extracting and analyzing biological informationof the subject using the selected signal.

The light may be irradiated onto the measurement area of the subject bydriving the at least two light emission elements to emit light atdifferent times, and the plurality of signals may be detected atdifferent times, corresponding to the different times at which the lightis emitted from the at least two light emission elements.

The light may irradiated onto the measurement area of the subject bysimultaneously driving the at least two light emission elements, and theplurality of signals may be detected using a plurality of lightreceiving devices different from each other.

The at least two light emission elements may include a first lightemission element and a second light emission element, the first lightemission element may include a first light source, and the second lightemission element may include a second light source of a different typewith respect to the first light source, and the first light source andthe second light source may have different light emission angles.

At least two light emission elements may include a first light emissionelement and a second light emission element, the first light emissionelement may include a first light source, and the second light emissionelement may include a second light source of same type as the firstlight source, and one of the first light emission element and the secondlight emission element may further include a lens configured to condenseor disperse light generated by the light source thereof.

According to an aspect of another exemplary embodiment, a method ofdetecting biological information may include irradiating a measurementarea of a subject with light output by at least one light emitting unithaving variable light emission angle, the at least one light emittingunit including a light source and a light emission angle control elementconfigured to control a light emission angle of the light source,generating a signal from light incident on and modulated by themeasurement area, and extracting and analyzing biological information ofthe subject using the generated signal.

The method may further include measuring a distance between the lightsource and the subject, and changing a light emission angle of the lightemitting unit according to the measured distance.

A plurality of signals corresponding to a plurality of light emissionangles may be generated from light detected while changing a lightemission angle of the light emitting unit, and after a signal having arelatively high signal-to-noise ratio (SNR) may be selected from amongthe generated signals, biological information of the subject isextracted and analyzed using the selected signal.

The light emission angle control element may include a variable focusinglens.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other exemplary aspects will become apparent and morereadily appreciated from the following description of exemplaryembodiments, taken in conjunction with the accompanying drawings inwhich:

FIG. 1 schematically illustrates a structure of an apparatus fordetecting biological information, according to an exemplary embodiment;

FIG. 2 is a graph showing an example of a surface pulse wave signalmeasured by a biological signal measurement unit, according to anexemplary embodiment;

FIG. 3 illustrates a light emission portion for use with the biologicalsignal measurement unit, according to an exemplary embodiment;

FIG. 4 illustrates a light emission portion for use with the biologicalsignal measurement unit, according to another exemplary embodiment;

FIG. 5 illustrates a light emission portion for use with the biologicalsignal measurement unit, according to another exemplary embodiment;

FIG. 6 illustrates light incident on a subject irradiated by the lightemission portion when the light emission portion of the biologicalsignal measurement unit is spaced apart, by a first distance, from asurface of the subject, according to an exemplary embodiment;

FIG. 7 illustrates light incident on a subject irradiated by the lightemission portion when the light emission portion of the biologicalsignal measurement unit is spaced apart, by a second distance, from thesurface of the subject, according to another exemplary embodiment;

FIG. 8 is a graph showing a change of a signal-to-noise ratio (SNR) of adetected signal according to the height (i.e. a separation distance froma subject) of each of a plurality of light emission elements (lightsources), according to an exemplary embodiment;

FIG. 9 illustrates a biological signal measurement unit for use with anapparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 10 illustrates a biological signal measurement unit for use with anapparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 11 illustrates a biological signal measurement unit for use with anapparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 12 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to an exemplary embodiment;

FIG. 13 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 14 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 15 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 16 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 17 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 18 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 19 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 20 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 21 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 22 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 23 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIGS. 24 and 25 illustrate examples of cases in which a biologicalsignal measurement unit is placed over a radial artery passing through awrist of a subject and performs measurement, according to an exemplaryembodiment;

FIG. 26 illustrates a light emission portion for use with the biologicalsignal measurement unit, according to another exemplary embodiment;

FIG. 27 illustrates a light emission portion for use with the biologicalsignal measurement unit, according to another exemplary embodiment;

FIG. 28 illustrates a biological signal measurement unit for use withthe apparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 29 is a block diagram showing a structure of the apparatus fordetecting biological information of FIG. 1, according to an exemplaryembodiment;

FIG. 30 is a block diagram showing a structure of the apparatus fordetecting biological information of FIG. 1, according to anotherexemplary embodiment;

FIGS. 31 to 33 are block diagrams showing modified examples of thestructure of FIG. 30;

FIG. 34 illustrates an example of a wearable device for use with theapparatus for detecting biological information, according to anexemplary embodiment;

FIG. 35 illustrates an example of a portable device for use with theapparatus for detecting biological information, according to anexemplary embodiment;

FIG. 36 is a flowchart explaining a method of detecting biologicalinformation, according to an exemplary embodiment;

FIG. 37 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 38 is a graph explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 39 is a graph explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 40 is a circuit diagram showing an example of a light emissionportion for use with the biological signal measurement unit, accordingto another exemplary embodiment;

FIG. 41 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 42 schematically illustrates a structure of an apparatus fordetecting biological information, according to another exemplaryembodiment;

FIG. 43 illustrates a structure of the light emitting unit of FIG. 42,according to an exemplary embodiment;

FIG. 44 is a cross-sectional view showing an example of a structure of alight emission angle control element of FIG. 43;

FIG. 45 is a plan view showing a structure of a biological signalmeasurement unit for use with the apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 46 is a plan view showing a structure of a biological signalmeasurement unit for use with the apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 47 is a plan view showing a structure of a biological signalmeasurement unit for use with the apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 48 is a plan view showing a structure of a biological signalmeasurement unit for use with the apparatus for detecting biologicalinformation, according to another exemplary embodiment;

FIG. 49 illustrates a biological signal measurement unit for use withthe apparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 50 illustrates a biological signal measurement unit for use withthe apparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 51 illustrates a biological signal measurement unit for use withthe apparatus for detecting biological information, according to anotherexemplary embodiment;

FIG. 52 is a block diagram showing a structure of the apparatus fordetecting biological information FIG. 42, according to an exemplaryembodiment;

FIG. 53 is a block diagram showing a structure of the apparatus fordetecting biological information FIG. 42, according to another exemplaryembodiment;

FIG. 54 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 55 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 56 is a graph showing two signals detected according to anexemplary embodiment and direct current (DC) levels thereof;

FIG. 57 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment;

FIG. 58 illustrates an apparatus for and method of detecting biologicalinformation, according to another exemplary embodiment; and

FIG. 59 illustrates an apparatus and method of detecting biologicalinformation, according to another exemplary embodiment.

DETAILED DESCRIPTION

Various exemplary embodiments will now be described more fully withreference to the accompanying drawings in which exemplary embodimentsare shown.

It should be understood that when an element is referred to herein asbeing “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element, or intervening elements maybe present. In contrast, when an element is referred to as being“directly connected” or “directly coupled” to another element, there areno intervening elements present. As used herein the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It should be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of example embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexemplary embodiments only and is not intended to be limiting of theexemplary embodiments. As used herein, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It should be further understoodthat the terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Exemplary embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized aspects (and intermediate structures) of exemplaryembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, exemplary embodiments should not be construedas limited to the particular shapes of regions illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofexemplary embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which exemplary embodiments belong. Itshould be further understood that terms, such as those defined incommonly-used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Reference will now be made in detail to an apparatus and system fordetecting biological information and a method of detecting biologicalinformation, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout. Also, the size of each element (or unit) illustrated in thedrawings may be exaggerated for convenience of explanation and clarity.In this regard, the presented exemplary embodiments may have differentforms and should not be construed as being limited to the descriptionsset forth herein. Accordingly, the exemplary embodiments are merelydescribed below, by referring to the figures, to explain aspects of thepresent description. In a structure, when a constituent element isdisposed “above” or “on” to another constituent element, the constituentelement may be only directly on the other constituent element or abovethe other constituent elements in a non-contact manner.

Hereinafter, an apparatus and system for detecting biologicalinformation and a method of detecting biological information will bedescribed more fully with reference to the accompanying drawings. Thewidth and thickness of a layer or region illustrated in the drawings maybe rather exaggerated for convenience of explanation. Like referencenumerals in the drawings denote like elements, throughout the followingdescription.

FIG. 1 schematically illustrates a structure of a biological informationdetection apparatus 1000, according to an exemplary embodiment. The term“biological information” may signify information of a living body. Thebiological information may include biological and medical informationthat may be obtained from a body of a subject SBJ, for example, a livingthing such as a human or an animal, which is a measurement subject ofthe biological information detection apparatus 1000, or a partialelement or component of the body.

Referring to FIG. 1, the biological information detection apparatus 1000may include a biological signal measurement unit M10 to measure abiological signal of the SBJ. Also, the biological information detectionapparatus 1000 may include a non-volatile memory (not shown) storinginstructions and a data processor configured to execute the instructionsand thereby extract and analyze biological information of the subjectSBJ from data measured by the biological signal measurement unit M10.The data processor may be provided within a processor (processor unit)P10. Also, the biological information detection apparatus 1000 mayfurther include a driver and signal converter DS10 connected to theprocessor P10 of the biological signal measurement unit M10. The driverand signal converter DS10 may include a light source driver and a signalconverter.

The biological signal measurement unit M10 may include a light emissionportion LT10 to irradiate predetermined light onto a measurement area ofthe subject SBJ. The light emission portion LT10 may include at leasttwo light emission elements LL10 and LL20 having light emission anglesof different sizes. For example, the light emission portion LT10 mayinclude a first light emission element LL10 having a first lightemission angle θ1 within which light is emitted and a second lightemission element LL20 having a second light emission angle θ2 withinwhich light is emitted. The first light emission angle θ1 and the secondlight emission angle θ2 may be different from each other. For example,the first light emission angle θ1 may be greater than the second lightemission angle θ2 by about 20° or more, or about 40° or more. In adetailed example, the first light emission angle θ1 may be about 60° to180°, and the second light emission angle θ2 may be about 0° to 100°.Alternatively, the first light emission angle θ1 may be about 80° to180°, and the second light emission angle θ2 may be about 0° to 90°.Alternatively, the first light emission angle θ1 may be about 100° to170°, and the second light emission angle θ2 may be about 5° to 50°. Theranges of the first and second light emission angles θ1 and θ2 areexemplary and may vary. The term “light emission angle” describes anangle defining a degree of spreading of light output by a light sourcein a predetermined direction toward the sides (to the periphery) withrespect to the irradiation direction. Accordingly, the “light emissionangle” may alternately be referred to as the divergence angle of light.Also, the “light emission angle” may alternately be referred to as theviewing angle. Light L10 output by the first light emission element LL10toward the subject SBJ may be referred to as the “first incident light”,and light L20 output by the second light emission element LL20 towardthe subject SBJ may be referred to as the “second incident light”. Thefirst light emission angle θ1 is an angle indicating a degree ofdivergence of the first incident light L10 from the first light emissionelement LL10, and the second light emission angle θ2 is an angleindicating a degree of divergence of the second incident light L20 fromthe second light emission element LL20. The structures of the first andsecond light emission elements LL10 and LL20 will be described laterwith reference to FIGS. 3 to 5.

The biological signal measurement unit M10 may further include aphotodetector (photodetecting portion) DT10 to detect light L50′ that isoutput by the light emission portion LT10 toward the subject SBJ andmodulated, for example, reflected or scattered, by the subject SBJ. Thelight L50′ may be referred to as the modulated light or the lightsignal. The photodetector DT10 may be arranged adjacent to the lightemission portion LT10 and may include at least one light receivingdevice. For example, a photodiode, a phototransistor, or acharge-coupled device (CCD) may be used as the light receiving device. Adistance between the photodetector DT10 and the light emission portionLT10 may be within, for example, several millimeters, or in some cases,about 10 mm or more.

A biological signal of the subject SBJ, measured by the biologicalsignal measurement unit M10 may be, for example, a surface pulse wave.The surface pulse wave may be a waveform (signal) corresponding to adegree of trembling of a surface (skin surface) of the subject SBJ dueto the contraction and relaxation of a blood vessel (BV1). The surfacepulse wave corresponding to the trembling of the surface S1 may bemeasured by detecting the light L50′ modulated on the surface S1 of thesubject SBJ. The surface pulse wave may be referred to as the “skinsurface pulse wave”. FIG. 2 is a graph showing an example of a surfacepulse wave signal measured by the biological signal measurement unitM10, according to an exemplary embodiment. The graph of FIG. 2 shows anexemplary result of measurement of a biological signal of the subjectSBJ using only the first light emission element LL10 of the first andsecond light emission elements LL10 and LL20. A biological signal of thesubject SBJ measured by the biological signal measurement unit M10 maybe a signal other than a surface pulse wave. For example, the biologicalsignal may be a photoplethysmogram (PPG) or other signal. Any biologicalsignal that is measurable by a non-invasive method using light may be asubject of measurement.

Data measured by the biological signal measurement unit M10 may betransferred to the processor P10. The data processor of the processorP10 may perform the function of extracting and analyzing biologicalinformation of the subject SBJ from the data. For example, variouspieces of biological information of the subject SBJ, such as, a systolicblood pressure, a diastolic blood pressure, a heart rate, a blood oxygensaturation, a blood vessel elasticity, a blood flow rate, or arterialstiffness, may be extracted and analyzed from the surface pulse wavesignal shown in FIG. 2. As illustrated in FIG. 2, various signalparameters such as a peak, a dicrotic notch, a number of signals perunit time, an augmentation index (AI), a reflective wave transit time(RWTT), a subendocardial viability ratio (SEVR), or an ejectionduration, may be extracted from the surface pulse wave signal andanalyzed (that is, using pulse wave analysis (PWA)), thereby obtainingvarious pieces of biological information. Also, according to the presentexemplary embodiment, the data processor may be configured to select asignal having a relatively high signal-to-noise ratio (SNR) from aplurality of detected signals measured by the light emission elementsLL10 and LL20, and to extract and analyze biological information of thesubject SBJ using the selected signal. Accordingly, the accuracy andreliability of the measurement may be improved.

The first and second light emission elements LL10 and LL20 forming thelight emission portion LT10 of FIG. 1 may include different types oflight sources having different light emission angles, and examplesthereof are illustrated in FIG. 3.

Referring to FIG. 3, a light emission portion LT11 may include a firstlight emission element LL11 and a second light emission element LL21.The first light emission element LL11 may include a first light sourceLS1, and the second light emission element LL21 may include a secondlight source LS2. The first light source LS1 may be the first lightemission element LL11, and the second light source LS2 may be the secondlight emission element LL21. A type of the first light source LS1 may bedifferent from that of the second light source LS2. In a detailedexample, the first light source LS1 may be a light emitting diode (LED),and the second light source LS2 may be a laser diode (LD). In this case,a light emission angle θ1 of the first light source LS1 may be, forexample, about 80° to 180°, about 100° to 170°, or about 120° to 170°. Alight emission angle θ2 of the second light source LS2 may be, forexample, about 0° to 90°, about 5° to 50°, or about 10° to 30°. LightL11 and light L21 are generated by the first light emission element LL11and the second light emission element LL21, respectively.

According to another exemplary embodiment, the first and second lightemission elements LL10 and LL20 forming the light emission portion LT10of FIG. 1 may include the same type of light source. For example boththe first and section light emission elements LL10 and LL20 may be LDs,or both may be LEDs. In this case, either one of the two light emissionelements LL10 and LL20 may further include an optical element (opticaldevice) to adjust the light emission angle. The optical element mayinclude at least one of, for example, a lens, an optical waveguide, aslit, a concave mirror, and a convex mirror. FIG. 4 illustrates anexample in which a lens structure is employed as the optical element.

Referring to FIG. 4, a light emission portion LT12 may include a firstlight emission element LL12 and a second light emission element LL22.The first light emission element LL12 may include a first light sourceLS1-1, and the second light emission element LL22 may include a secondlight source LS1-2 that is the same type of light source as the firstlight source LS1-1. Both of the first light source LS1-1 and the secondlight source LS1-2 may be LEDs or LDs. Either of the first and secondlight emission elements LL12 and LL22, for example, the second lightemission element LL22, may further include a lens structure LN2 tocondense or disperse light generated by the light source correspondingthereto, that is, the second light source LS1-2. The lens structure LN2may include at least one lens and generally have a positive (+)refractive power or a negative (−) refractive power. A lens may beomitted from the other one of the first and second light emissionelements LL12 and LL22, for example, the first light emission elementLL12. In other words, while the first light source LS1-1 may be usedwithout a lens, the second light source LS1-2 that is the same type ofthe first light source LS1-1 may be used with the lens structure LN2.Accordingly, first light emission element LL12 and the second lightemission element LL22 may have different light emission angles θ1 andθ2. Although the second light source LS1-2 and the lens structure LN2are illustrated as being in contact with each other, they may be spacedapart from each other by a predetermined interval. Light L12 and lightL22 are generated by the first light emission element LL12 and thesecond light emission element LL22, respectively.

According to another exemplary embodiment, the first light emissionelement LL12 of FIG. 4 may include a lens structure, and an examplethereof is illustrated in FIG. 5.

Referring to FIG. 5, a light emission portion LT13 may include a firstlight emission element LL13 and a second light emission element LL23.The first light emission element LL13 may include a first light sourceLS1-1′, and the second light emission element LL23 may include a secondlight source LS1-2′ that is the same type of light source as the firstlight source LS1-1′. The first light emission element LL13 may furtherinclude a first lens structure LN1′ to condense or disperse lightgenerated by the first light source LS1-1′. The second light emissionelement LL23 may further include a second lens structure LN2′ tocondense or disperse light generated by the second light source LS1-2′.The first lens structure LN1′ and the second lens structure LN2′ mayhave opposite refractive powers. The signs of the refractive powers ofthe first lens structure LN1′ and the second lens structure LN2′ may beopposite to each other. For example, the first lens structure LN1′ mayhave a negative (−) refractive power, and the second lens structure LN2′may have a positive (+) refractive power. Alternatively, the first andsecond lens structures LN1′ and LN2′ may have different refractivepowers of the same sign. When different lens structures LN1′ and LN2′are applied to the same type of the two light sources LS1-1′ and LS1-2′,the two light emission elements LL13 and LL23 including the aboveelements may have different light emission angles θ1 and θ2. Light L13and light L23 are generated by the first light emission element LL13 andthe second light emission element LL23, respectively.

As described above with reference to FIG. 4, an optical element, thatis, the lens structure LN2 configured to adjust the light emissionangle, may be provided in any one of the first light emission elementLL12 and the second light emission element LL22, or as described abovewith reference to FIG. 5, a first optical element, that is, the firstlens structure LN1′, is provided in the first light emission elementLL13, and a second optical element, that is, the second lens structureLN2′, which is different from the first optical element LN1′, may beprovided in the second light emission element LL23. In addition to or inplace of a lens structure as described above, an optical waveguide, aslit, a concave mirror, or a convex mirror may be used as the opticalelement, or a combination of two or more of a lens structure, an opticalwaveguide, a slit, a concave mirror, and a convex mirror may be used.Also, the optical element may be applied to at least one of the firstlight emission element LL11 and the second light emission element LL21of FIG. 3.

In an exemplary embodiment, a biological signal of a subject may bemeasured using a plurality of light emission elements (light sources)having different light emission angles. In this way, optimalillumination intensity and an optimal light irradiation area may beensured regardless of a distance between a biological signal measurementunit (sensor) and a measurement surface of a subject, which will bedescribed with reference to FIGS. 6 and 7.

FIG. 6 illustrates light irradiated onto the subject SBJ by the lightemission portion LT10 when the light emission portion LT10 of thebiological signal measurement unit M10 is spaced apart from a surface (ameasurement surface) S1 of the subject SBJ by a first distance d1,according to an exemplary embodiment. In the present exemplaryembodiment. As compared with FIG. 7, the light emission portion (lightsource unit) LT10 of FIG. 6 is located relatively far from themeasurement surface S1.

Referring to FIG. 6, when the light emission portion (light source unit)LT10 is located relatively far from the measurement surface S1, thesecond light emission element LL20 having a narrow light emission angleθ2, that is, a narrow viewing angle θ2, may be advantageous to secureoptimal illumination intensity and an optimal light irradiation area formeasurement of optimal biological signal.

FIG. 7 illustrates light irradiated onto the subject SBJ by the lightemission portion LT10 when the light emission portion LT10 of thebiological signal measurement unit M10 is spaced apart from themeasurement surface S1 of the subject SBJ by a second distance d2,according to an exemplary embodiment. In the present exemplaryembodiment, as compared with FIG. 6, the light emission portion (lightsource unit) LT10 is located relatively close to the measurement surfaceS1.

Referring to FIG. 7, when the light emission portion (light source unit)LT10 is located relatively close to the measurement surface S1, thefirst light emission element LL10 having a wide light emission angle θ1,that is, a wide viewing angle θ1, may be advantageous to secure optimalillumination intensity and an optimal light irradiation area formeasurement of optimal biological signal.

When measurement is performed using only one light source having asingle light emission angle, because the light source is far away fromor close to a measurement surface of the subject, the illuminationintensity and the light irradiation area vary and may exceed optimalmeasurement conditions and thus the SNR of the thus obtained signal maybe lowered. However, in the present exemplary embodiment, by using aplurality of emission elements (light sources) having different lightemission angles, regardless of the distance between the measurement unit(biological signal measurement unit) and the measurement surface of thesubject, an optimal illumination intensity and an optimal lightirradiation area may be secured and thus a detected signal having a highSNR may be obtained.

FIG. 8 is a graph showing a change of an SNR of a detected signalaccording to the height of each of the light emission elements (lightsources), that is, a separation distance from the subject, according toan exemplary embodiment. The light emission portion LT10 used in thepresent exemplary embodiment may include an LED as the first lightemission element LL10 and an LD as the second light emission elementLL20. The light emission portion LT10 may correspond to the lightemission portion LT11 of FIG. 3. In this case, both of the LED and theLD are infrared (IR) sources for generating IR light.

Referring to FIG. 8, when a distanced is 5.5 mm, it may be seen that asignal detected using light output by the second light emission elementLL20, having a narrow light emission angle, has a relatively high SNR,which may correspond to the case described with reference to FIG. 6.Alternatively, when the distance d is 2.5 mm, it may be seen that asignal detected using light output by the first light emission elementLL10, having a wide light emission angle, has a comparatively high SNR,which may correspond to the case described with reference to FIG. 7.Accordingly, when a distance between the measurement unit and themeasurement surface of the subject is relatively long, that is, thedistance d is large, a signal having a comparatively high SNR may beobtained by using the second light emission element LL20. When thedistance between the measurement unit and the measurement surface of thesubject is relatively short, that is, the distance d is small, a signalhaving a comparatively high SNR may be obtained by using the first lightemission element LL10. Accordingly, a biological signal having superiorquality may be measured regardless of the separation distance betweenthe measurement unit and the measurement surface of the subject. As aresult, accuracy and reliability in the measurement may be greatlyimproved. Based on FIG. 8 and experiment results similar thereto, whenthe distance d is equal to or greater than about 4.5 mm or about 4 mm, asignal detected using light output by the second light emission elementLL20 may have a comparatively high SNR. Also, when the distance d isequal to or less than about 3.5 mm or about 4 mm, a signal detectedusing light output by the first light emission element LL10 may have acomparatively high SNR.

Alternatively, in FIG. 8, when the distance d is 0 mm, that is, thebiological signal measurement unit and the measurement surface of thesubject are in contact with each other, the trembling of a measurementsurface, that is, a skin surface, may be limited by the biologicalsignal measurement unit itself, and a low SNR may be measured usinglight output by both of the light emission elements LL10 and LL20. Inthis case, as illustrated in FIG. 9, a spacer SP1 may be used to preventthe biological signal measurement unit from contacting the measurementsurface, that is, a skin surface.

Referring to FIG. 9, a biological signal measurement unit M1 may beprovided on a predetermined support SS1. The support SS1 may be asubstrate. The substrate may be, for example, a printed circuit board(PCB) or a substrate similar thereto. The support SS1 may have aflexible or rigid structure. The biological signal measurement unit M1may have a structure that is the same as or similar to that of thebiological signal measurement unit M10 of FIG. 1. Accordingly, thebiological signal measurement unit M1 may include a light emissionportion LT1 having at least two light emission elements LL1 and LL2having different light emission angles, and may further include aphotodetector DT1. The photodetector DT1 may include at least one lightreceiving device. Also, according to the present exemplary embodiment,at least one spacer SP1, protruding to one side of the support SS1, maybe provided. The light emission portion LT1 and the photodetector DT1may be spaced apart from the measurement surface S1 of the subject SBJby the spacer SP1. In other words, a minimum separation distance betweenthe light emission portion LT1 and the photodetector DT1, and themeasurement surface S1, may be secured by the spacer SP1. Accordingly,the problem of an SNR of a measured signal being reduced as the lightemission portion LT1 and the photodetector DT1 contact the measurementsurface S1 may be prevented. In the present exemplary embodiment, thebiological signal measurement unit M1 may be considered to include allof the support SS1, the light emission portion LT1, the photodetectorDT1, and the spacer SP1.

In FIG. 9, the use of the spacer SP1 is exemplary and another method maybe used to achieve the purpose of forming the spacer SP1. Also, theforming position, structure, and number of the spacer SP1 are exemplaryand may be changed in any of various ways. Also, in FIG. 9, thestructure of the light emission portion LT1 and the photodetector DT1being embedded in the support SS1 is exemplary, and the depth orposition of embedding may be changed.

FIG. 9 exemplarily illustrates an apparatus for measuring an effectivemeasurement surface of the subject SBJ using a non-contact method. Whena biological signal such as a surface pulse wave of the subject SBJ ismeasured, a non-contact measurement method may be employed. However,when a photoplethysmogram (PPG) signal is detected, rather than asurface pulse wave, a contact measurement method may be employed insteadof the non-contact measurement method. In this case, the spacer SP1 maybe omitted, and a biological signal may be measured in a state in whichthe measurement unit M1 (LT1+DT1) is in contact with the effectivemeasurement surface of the subject SBJ. Thus, the measurement method maybe changed according to a biological signal to be measured.

According to the present exemplary embodiment, the photodetector DT10 ofFIG. 1 may include a light receiving device capable of receiving anoptical signal from the first light emission element LL10 and an opticalsignal from the second light emission element LL20. Alternatively, thephotodetector DT10 may include a first light receiving device thatselectively receives the optical signal from the first light emissionelement LL10 and a second light receiving device that selectivelyreceives the optical signal from the second light emission element LL20.FIG. 10 exemplarily illustrates the former and FIG. 11 exemplarilyillustrates the latter.

Referring to FIG. 10, a photodetector DT11 may include a light receivingdevice PD11. The light receiving device PD11 may receive both of anoptical signal (hereinafter, referred to as the first optical signal)L10′ generated by the subject SBJ by incident light (hereinafter,referred to as the first incident light) L10 from the first lightemission element LL10, and an optical signal (hereinafter, referred toas the second optical signal) L20′ generated by the subject SBJ byincident light (hereinafter, referred to as the second incident light)L20 from the second light emission element LL20. In this case, the firstoptical signal L10′ and the second optical signal L20′ may be incidenton the light receiving device PD11 at different times. By driving thefirst light emission element LL10 and the second light emission elementLL20 at different timings, the first incident light L10 and the secondincident light L20 may be irradiated onto the surface S1 of the subjectSBJ with at different times. As a result, first optical signal L10′ andthe second optical signal L20′ may be detected by the light receivingdevice PD11 at different times. In this case, a plurality of signalsdetected by a plurality of light emission elements LL10 and LL20 may bedivided using a time-division method.

Referring to FIG. 11, a photodetector DT12 may include a first lightreceiving device PD1 and a second light receiving device PD2. The firstlight receiving device PD1 may be configured to selectively receive afirst optical signal L10′ generated in the subject SBJ from the firstincident light L10 of the first light emission element LL10. The secondlight receiving de vice PD2 may be configured to selectively receive asecond optical signal L20′ generated in the subject SBJ from the secondincident light L20 of the second light emission element LL20. In thiscase, the first incident light L10 and the second incident light L20 mayfall within different wavelength ranges. The first optical signal L10′may fall within a wavelength range corresponding to the first incidentlight L10, and the second optical signal L20′ may fall within awavelength range corresponding to the second incident light L20. In adetailed example, the first incident light L10 and the first opticalsignal L10′ may fall within a wavelength range corresponding to any oneof regions of red R, green G, blue B, and infrared IR light. The secondincident light L20 and the second optical signal L20′ may fall within awavelength range corresponding to another of the regions of red R, greenG, blue B, and infrared IR light. Each of the first and second lightreceiving devices PD1 and PD2 may include a device for filtering lightof a particular wavelength range. The first light receiving device PD1may selectively receive the first optical signal L10′ and the secondlight receiving device PD2 may selectively receive the second opticalsignal L20′, using their respective filtering devices. In the presentexemplary embodiment, a plurality of signals detected by the lightemission elements LL10 and LL20 may be divided using awavelength-division method. In this case, unlike the above-describedtime-division method, the first and second light emission elements LL10and LL20 may be driven simultaneously.

According to the present exemplary embodiment, the light emissionportion may include two or more light emission elements (light sources),and the photodetector may include two or more light receiving devices.In the following description, referring to FIGS. 12 to 23, various planestructures (array structures) of the biological signal measurement unitare described.

FIG. 12 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to an exemplary embodiment.

Referring to FIG. 12, a light emission portion 100A may include a firstlight emission element 10 and a second light emission element 20. Thefirst light emission element 10 and the second light emission element 20may correspond to the first light emission element LL10 and the secondlight emission element LL20 of FIG. 1, respectively. A plurality oflight receiving devices 200 may be provided on the biological signalmeasurement unit around or near the light emission portion 100A. Forexample, two light receiving devices 200 may be provided, one at each ofopposite sides of the light emission portion 100A. A plurality of lightreceiving devices 200 may constitute one photodetector. Each of thelight receiving devices 200 may correspond to the light receiving devicePD11 described in FIG. 10. Photodiodes, phototransistors, orcharge-coupled devices (CCDs) may be used as the light receiving devices200. The light emission portion 100A and the light receiving devices 200may be provided on or in a substrate 1. The substrate 1 may be, forexample, a PCB, or another substrate as would be understood by one ofskill in the art. The substrate 1 may be a sort of support.

Although FIG. 12 illustrates a case in which the light receiving devices200 are provided at opposite sides of the light emission portion 100A,as illustrated in FIG. 13, four light receiving devices 200 may beprovided, one at each of the upper, lower, left, and right sides of thelight emission portion 100A. In other words, the light receiving devices200 may be arranged in at least four positions around the light emissionportion 100A.

In FIGS. 12 and 13, the light emission portion 100A may include aplurality of first light emission elements 10 and a plurality of secondlight emission elements 20, and FIG. 14 illustrates an example thereof.Referring to FIG. 14, a light emission portion 100B may include atwo-dimensional (2D) array in which a plurality of first light emissionelements 10 and a plurality of second light emission elements 20 aremixed.

Also, according to another exemplary embodiment, in the structures ofFIGS. 12 to 14, a plurality of light receiving devices 200 may bearranged in an annular array around the light emission portions 100A and100B, and FIGS. 15 and 16 illustrate examples thereof.

FIG. 17 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment.

Referring to FIG. 17, the light emission portion 100A may include thefirst light emission element 10 and the second light emission element20. A plurality of light receiving device regions 210 may be providedaround the light emission portion 100A. Each of the light receivingdevice regions 210 may include a first light receiving device 200 a anda second light receiving device 200 b. The first light receiving device200 a may be a device receiving an optical signal from one of the firstand second light emission elements 10 and 20. The second light receivingdevice 200 b may be a device receiving an optical signal from the otherof the first and second light emission elements 10 and 20. The firstlight receiving device 200 a and the second light receiving device 200 bmay be configured to receive optical signals having different wavelengthranges. The first light receiving device 200 a and the second lightreceiving device 200 b may correspond to the first light receivingdevice PD1 and the second light receiving device PD2 of FIG. 11. In anexample, the first light receiving device 200 a may be a devicereceiving an optical signal in a red R region, and the second lightreceiving device 200 b may be a device receiving an optical signal in agreen G region. In this case, one of the first and second light emissionelements 10 and 20 may be a red light source, and the other one may be agreen light source. However, the light emission wavelengths of the firstand second light emission elements 10 and 20 and the light receivingwavelengths of the first and second light receiving devices 200 a and200 b are not limited to these specific wavelengths, and may be changedin various ways.

The structure of FIG. 17 may be modified in a way as illustrated in FIG.18. Referring to FIG. 18, a light emission portion 100C may include aplurality of first light emission elements 10-1 and 10-2 and a pluralityof second light emission elements 20-2 and 20-2. The first lightemission elements 10-1 and 10-2 may include a (1-1)th light emissionelement 10-1 and a (1-2)th light emission element 10-2. The (1-1)thlight emission element 10-1 and the (1-2)th light emission element 10-2may generate light of different wavelength ranges. A plurality of secondlight emission elements 20-1 and 20-2 may include a (2-1)th lightemission element 20-1 and a (2-2)th light emission element 20-2. The(2-1)th light emission element 20-1 and the (2-2)th light emissionelement 20-2 may generate light of different wavelength ranges. Aplurality of light receiving device regions 220 may be provided aroundthe light emission portion 100C. Each of the light receiving deviceregions 220 may include first through fourth light receiving devices 201a to 201 d. The first through fourth light receiving devices 201 a to201 d may be configured to receive optical signals of differentwavelength ranges. For example, the first through fourth light receivingdevices 201 a to 201 d may be configured to receive optical signals inwavelength ranges of red R, green G, blue B, and infrared IR light. Thelight emission wavelengths of the light emission elements 10-1, 10-2,20-2, and 20-2 may be determined in order to correspond with thewavelength ranges of the received optical signals.

In FIGS. 17 and 18, the light receiving device regions 210 and 220 maybe arranged in an annular array around the light emission portions 100Aand 100B, and FIGS. 19 and 20 illustrate examples thereof. Thearrangement method of the R and G regions of the light receiving deviceregion 210 of FIGS. 17 and 19, and the arrangement method of the R, G,B, and IR regions of the light receiving device region 220 of FIGS. 18and 20, are exemplary and may be altered.

FIG. 21 is a plan view showing a structure of a biological signalmeasurement unit for use with an apparatus for detecting biologicalinformation, according to another exemplary embodiment.

Referring to FIG. 21, the light emission portion 100A and the lightreceiving devices 200 arrayed around the light emission portion 100Aform one sub-unit SU1. A plurality of sub-units SU1 may be repeatedlyarranged. The light emission portion 100A may include at least one firstlight emission element 10 and at least one second light emission element20. In each sub-unit SU1, the light receiving devices 200 may bearranged around the light emission portion 100A in a hexagonal array orin another shape. Two adjacent sub-units SU1 may share some of the lightreceiving devices 200. However, the structure of the sub-unit SU1 andthe repetitive arrangement method of the sub-unit SU1 in FIG. 21 may bemodified in various ways.

FIG. 22 is a plan view of a structure of a biological signal measurementunit for use with an apparatus for detecting biological information,according to another exemplary embodiment.

Referring to FIG. 22, a light emission portion 110 may have a structurein which a plurality of first light emission elements 10 and a pluralityof second light emission elements 20 are mixed in at least one line. Thefirst light emission elements 10 and the second light emission elements20 may be alternately arranged in a predetermined direction. A pluralityof light receiving devices 201 may be provided around the light emissionportion 110. The light receiving devices 201 may be arranged forming anarray at at least one side of the light emission portion 110. Forexample, light receiving device arrays 210 a and 210 b, each including aplurality of the light receiving devices 201, may be provided atopposite sides of the light emission portion 110.

The array structure of FIG. 22 may be changed in various ways. Forexample, although FIG. 22 illustrates that the first and second lightemission elements 10 and 20 of the light emission portion 110 forming anarray of a single line, an array of two or more lines may be formed, andFIG. 23 illustrates an example thereof. Referring to FIG. 23, a lightemission portion 120 may have a structure in which a plurality of thefirst light emission elements 10 and a plurality of the second lightemission elements 20 are mixed in an array forming two lines. The lightreceiving devices 201 may be arranged around and/or adjacent to thelight emission portion 120 as shown in FIG. 23.

The biological signal measurement units having various structuresdescribed with reference to FIGS. 12 to 23 may be applied to themeasurement area of a subject in various ways. The measurement area of asubject may be, for example, a specific portion of a human body. Afterthe biological signal measurement unit is brought close to a specificportion of a human body, a biological signal may be measured. FIGS. 24and 25 illustrate examples in which the biological signal measurementunit is placed over a radial artery RA1 passing through a wrist part ofa subject and performs measurement, according to an exemplaryembodiment. FIG. 24 illustrates a case of using the biological signalmeasurement unit corresponding to FIG. 13, and FIG. 25 illustrates acase of using the biological signal measurement unit corresponding toFIG. 22. However, the measurement positions illustrated in FIGS. 24 and25 are exemplary and may be changed. For example, the measurement may beperformed with respect to other parts of a subject such as a finger, atoe, an earlobe, etc., having a high blood vessel density in a humanbody, instead of the radial artery RAL

The various plane structures (array structures) of the measurement unitdescribed with reference to FIGS. 12 to 23 are exemplary and may bemodified in various ways. Additionally, when a pair of a light-emittingdevice (light source) and a light receiving device corresponding theretoor a set of at least one light-emitting device and at least one lightreceiving device forms one measurement unit, a plurality of measurementunits may be located at different areas of a subject. In this case, whena pulse wave signal is measured in different areas of an a subject usingthe measurement unit, a pulse transit time (PTT) may be obtained using atime difference between measured pulse wave signals and may be used forvarious biological information analyses.

In the above-described biological signal measurement unit applied to theapparatus for detecting biological information, the first light emissionelement (first light source) (LL10) and the second light emissionelement (second light source) (LL20) may be located at the same height(distance) from a reference surface or at difference heights(distances). FIG. 26 illustrates a case in which the first lightemission element LL10 and the second light emission element LL20 arelocated at the same height (distance) h from a reference surface S10.FIG. 27 illustrates a case in which the first light emission elementLL10 and the second light emission element LL20 are located at differentheights (distances) h1 and h2 from the reference surface S10.

FIG. 28 illustrates a biological signal measurement unit M20 for usewith the apparatus for detecting biological information, according toanother exemplary embodiment.

Referring to FIG. 28, the biological signal measurement unit M20 mayinclude a light emission portion LT20 and a photodetector DT20. Thelight emission portion LT20 may include at least three light emissionelements LL10, LL20, and LL30 having different light emission angles(viewing angles). The first light emission element LL10, the secondlight emission element LL20, and the third light emission element LL30may have different light emission angles. The first light emissionelement LL10 and the second light emission element LL20 may correspondto the first light emission element LL10 and the second light emissionelement LL20 of FIG. 1, respectively. The third light emission elementLL30 may have a light emission angle different from that of the firstand second light emission elements LL10 and LL20. In a detailed example,the first light emission element LL10 may include a first LED, thesecond light emission element LL20 may include a first LD, and the thirdlight emission element LL30 may include a second LED or a second LD. Inthis case, the second LED (or second LD) may have a light emission angledifferent from that of the first LED (or first LD). At least one of thefirst through third light emission elements LL10, LL20, and LL30 mayinclude an optical element to adjust the light emission angle similar tothe one described with reference to FIGS. 4 and 5. Alternatively,although only one photodetector DT20 is illustrated at one side of thelight emission portion LT20, a plurality of photodetectors DT20 may beprovided around the light emission portion LT20. When three or morelight emission elements LL10, LL20, LL30, having different lightemission angles (viewing angles), are used as in the present exemplaryembodiment, the accuracy and reliability of the measurement may befurther improved.

FIG. 29 is a block diagram showing a structure of the biologicalinformation detection apparatus 1000 of FIG. 1, according to anexemplary embodiment.

Referring to FIG. 29, a biological information detection apparatus 1000Amay include the biological signal measurement unit M10. The biologicalsignal measurement unit M10 may have the structure of the biologicalsignal measurement unit M10 of FIG. 1 or may be modified according toany other various structures in view of the above descriptions. Thebiological information detection apparatus 1000A may include a processorP10 including a data processor DP10 that extracts and analyzesbiological information of a subject from the data measured by thebiological signal measurement unit M10. The processor P10 may include acontroller CL10 for controlling an overall operation of the biologicalinformation detection apparatus 1000A.

The biological information detection apparatus 1000A may include a lightsource driver DD10 connected to the biological signal measurement unitM10. The light source driver DD10 may drive or control a plurality oflight emission elements LL10 and LL20 of the light emission portionLT10. The light source driver DD10 may be connected to the processorP10. The biological information detection apparatus 1000A may include asignal converter SC10 that is connected between the biological signalmeasurement unit M10 and the processor P10. The signal converter SC10may be connected to the light source driver DD10. The signal converterSC10 may include, for example, an analog front-end (AFE) circuit. Thesignal converter SC10 may convert an analog signal input by themeasurement unit M10 to a digital signal and may transmit the digitalsignal to the data processor DP10 of the processor P10. The signalconverter SC10 may include a signal amplifier, a noise filter, ananalog-to-digital (AD) converter, etc. A detected signal measured by themeasurement unit M10 may be amplified by the signal amplifier, removedof noise by the noise filter, and converted to a digital signal by theAD converter. A combination of the light source driver DD10 and thesignal converter SC10 may be regarded as one driver and signalconverter, which may correspond to the driver and signal converter DS10of FIG. 1. The light source driver DD10 and the signal converter SC10may be formed together in one chip (device) or may be formed separately.

The data processor DP10 may use an algorithm to select a signal having ahigh SNR and superior quality from among a plurality of detected signalsmeasured by the light emission elements LL10 and LL20. The dataprocessor DP10 may be configured to select a signal having a high SNRand superior quality using the algorithm. Also, the data processor DP10may be configured to extract and analyze biological information of asubject using the selected signal or using the entire detected signals.For example, when the signal measured by the biological signalmeasurement unit M10 is the surface pulse wave signal of FIG. 2, varioussignal parameters such as a peak, a dicrotic notch, number of signalsper unit time, an augmentation index (AI), a reflective wave transittime (RWTT), a subendocardial viability ratio (SEVR), or an ejectionduration may be extracted from the surface pulse wave signal andanalyzed (for example, using pulse wave analysis (PWA)), therebyobtaining various pieces of biological information of a subject, suchas, a systolic blood pressure, a diastolic blood pressure, a heart rate,a blood oxygen saturation, a blood vessel elasticity, a blood flow rate,or arterial stiffness. Since a well-known algorithm may be used toextract various signal parameters from pulse wave signal by the dataprocessor DP10, a detailed description thereof is omitted.

The controller CL10 of the processor P10 may control overall operationsof the light source driver DD10, the signal converter SC10, and the dataprocessor DP10. Although not illustrated, the processor P10 may furtherinclude data communication unit and/or memory. The data communicationunit may transmit biological information obtained through the dataprocessor DP10 to an external device. Also, the data communication unitmay receive a predetermined input signal from the external device. Thememory may store the information obtained by the data processor DP10,store a program for the data processor DP10 and the controller CL10, orstore a user's command.

FIG. 30 is a block diagram showing a structure of a biologicalinformation detection apparatus 1000B, according to another exemplaryembodiment.

Referring to FIG. 30, as described in FIG. 29, the biologicalinformation detection apparatus 1000B may include the biological signalmeasurement unit M10, the light source driver DD10, the signal converterSC10, and the processor P10. The biological information detectionapparatus 1000B of the present exemplary embodiment may further includean input unit IN10, an output unit OUT10, a memory MR10, and acommunication unit CM10, which are connected to the processor P10.

The input unit IN10 may be a device used by a user to input a command tothe biological information detection apparatus 1000B and may be, forexample, a keypad, a touch screen, a speech recognition device, or abutton type input device. The output unit OUT10 is a device foroutputting a result of analysis by the biological information detectionapparatus 1000B and may be, for example, a display device, a soundsystem, a vibration device, or a printer. The input unit IN10 and theoutput unit OUT10 together may be referred to as the user interface. Theuser may be a target of which biological information is to be measured,that is, the subject, or a person who may use the biological informationdetection apparatus 1000B, for example, a medical expert, which mayinclude a wider array of people than just the subject.

The memory MR10 may store a user's command and/or a result of analysis.Also, the memory MR10 may store a program for the data processor DP10and the controller CL10. For example, the memory MR10 may include atleast one of storage medium such as flash memory, a hard disc, amultimedia card (MMC), card type memory such as SD or XD memory, randomaccess memory (RAM), static random access memory (SRAM), read-onlymemory (ROM), electrically erasable programmable read-only memory(EEPROM), programmable read-only memory (PROM), magnetic memory, amagnetic disc, and an optical disc.

The communication unit CM10 may be configured to transmit the analyzedresult (data) to other external device. The external devicecommunicating with the communication unit CM10 may be, for example, amedical apparatus using analyzed biological information, or a printerthat prints the result. The external device may be a smartphone (mobilephone), a personal digital assistant (PDA), a laptop computer, apersonal computer (PC), and other mobile or non-mobile computing device,but is not limited thereto.

The communication unit CM10 may be connected to an external device bywire or wirelessly. For example, the communication unit CM10 maycommunicate with an external device by a communication method such asBluetooth communication, Bluetooth low energy (BLE) communication, nearfield communication, wireless local area network (WLAN) (wireless LAN)communication, Zigbee communication, infrared data association (IrDA)communication, Wi-Fi direct (WFD) communication, ultra-wideband (UWB)communication, ANT/ANT+ communication, or Wi-Fi communication, but notlimited thereto.

In FIG. 30, the output unit OUT10 may be provided in a separate deviceoutside the biological information detection apparatus 1000B, and FIG.31 illustrates an example thereof. Referring to FIG. 31, the output unitOUT10 may be provided in another device separate from the biologicalinformation detection apparatus 1000C and may receive data (biologicalinformation) through communication with the communication unit CM10.

According to another exemplary embodiment, in FIG. 30, both of the inputunit IN10 and the output unit OUT10 may be provided in separate devicesoutside the biological information detection apparatus 1000B and FIG. 32illustrates an example thereof. Referring to FIG. 32, the input unitIN10 and the output unit OUT10 may be provided in a separate deviceoutside a biological information detection apparatus 1000D, and mayexchange input information and output information through datacommunication with the communication unit CM10.

According to another exemplary embodiment, in FIG. 30, the memory MR10and the communication unit CM10 may be provided inside the processorP10. In some cases, at least one of the memory MR10 and thecommunication unit CM10 may be omitted, and FIG. 33 illustrates anexample thereof. Referring to FIG. 33, a biological informationdetection apparatus 1000E may include the input unit IN10 and the outputunit OUT10, which are connected to the processor P10. Although notillustrated, the processor P10 may further include at least one of thememory MR10 and the communication unit CM10. The biological informationdetection apparatuses 1000A to 1000E described with reference to FIGS.29 to 33 may be referred to as the biological information detectionsystem. Also, in FIGS. 29 to 33, the processor P10 may be connected tothe signal converter SC10 and/or the light source driver DD10 throughwireless communication.

At least some of the above-described biological information detectionapparatuses may form at least a part of a portable device or a wearabledevice. The portable device may be, for example, a mobile phone, and thewearable device may be, for example, a wristwatch type device, awristband type device, or a bracelet type device, or may take any ofvarious forms, such as glasses, a hairband, or a ring.

FIG. 34 illustrates an example of a wearable device in which theapparatus for detecting biological information is useable, according toan exemplary embodiment. In the present exemplary embodiment, thewearable device is a wristwatch type device.

Referring to FIG. 34, a wristwatch type device may include a device mainbody part (watch part) W10 and a band part B10. At least a part of anapparatus for detecting biological information according to the presentexemplary embodiment may be disposed in the band part B10 or in thedevice main body part W10, or parts of the apparatus may be disposed ineach of the band part B10 and the device main body part W10.

FIG. 35 illustrates an example of a portable device for use with theapparatus for detecting biological information, according to anexemplary embodiment. In the present exemplary embodiment, the portabledevice is a mobile phone.

In FIG. 35, the left image shows the front surface of a mobile phone andthe right image shows a rear surface of the mobile phone. Themeasurement unit (biological signal measurement unit) of the apparatusfor detecting biological information according to the present exemplaryembodiment may be exposed in the front surface or rear surface of themobile phone. Alternatively, the measurement unit may be exposed in aside surface (including an upper, lower, left, or right surface) of themobile phone.

A part of the apparatus for detecting biological information accordingto another exemplary embodiment may be provided in the wearable device(wristwatch type device) of FIG. 34, and another part may be provided inthe portable device (mobile phone) of FIG. 35. Also, the wearable deviceand the portable device may interact with each other and datacommunication may be performed therebetween.

The biological information detection apparatuses (or biologicalinformation detection systems) according to the present exemplaryembodiments may be used not only with a portable device or a wearabledevice, as described with reference to FIGS. 34 and 35, but also may beused with or as medical equipment used in hospitals or healthexamination organizations, middle- or small-sized medical equipmentprovided in public organizations, and compact medical equipment andvarious health-care apparatuses that may be possessed by an individual.

In the following description, biological information detection methodsaccording to exemplary embodiments will be described below.

FIG. 36 is a flowchart explaining a method of detecting biologicalinformation, according to an exemplary embodiment. The followingdescription with reference to FIG. 36 is related to the biologicalinformation detection apparatus described with reference to FIGS. 1 to35 and relevant descriptions thereof. Accordingly, the method of FIG. 36may be understood based on the descriptions of FIGS. 1 to 35.

Referring to FIG. 36, the method of detecting biological informationaccording to the present exemplary embodiment may include irradiating ameasurement area of a subject with a plurality of lights (incidentlights) having different light emission angles to using at least twolight emission elements having different light emission angles (S100),detecting a plurality of signals generated by the plurality of lightsbeing reflected by the measurement area (S200), and selecting a signalhaving a high SNR from among the detected signals and extracting andanalyzing biological information of the subject using the selectedsignal (S300). In the operation S100, the at least two light emissionelements having different light emission angles may correspond to, forexample, the two light emission elements LL10 and LL20 of FIG. 1. Thedetection of signals in operation S200 may be performed by, for example,the photodetectors DT10, DT11, and DT12 of FIGS. 1, 10, and 11. Theextraction and analysis of the biological information in the operationS300 may be performed by, for example, the data processor DP10 of FIGS.1 and 29.

According to the present exemplary embodiment, in the operation S100,the measurement area of the subject may be irradiated with the lights atdifferent times by driving the at least two light emission elements atdifferent times. Likewise, in conjunction with the operation S100, inthe operation S200, the signals may be detected at different times. Themethod may be summarized as shown in a flowchart of FIG. 37.

Referring to FIG. 37, a method of detecting biological informationaccording to the present exemplary embodiment may include irradiating ameasurement area of a subject with a plurality of lights (incidentlights) by driving at least two light emission elements at differenttimes (S101), detecting, at different times, a plurality of signalsgenerated by the lights being reflected from the subject (S201), andselecting a signal having a high SNR from among the detected signals andextracting and analyzing biological information of the subject using theselected signal (S301).

When, as in the operation S101, two light emission elements are drivenat different times, on and off (ON and OFF) operations of the two lightemission elements (light sources) may be performed as illustrated in,for example, FIG. 38. Referring to FIG. 38, as time passes, a firstlight emission element (first light source) and a second light emissionelement (second light source) may be alternately driven. As such, byalternately driving the first light emission element and the secondlight emission element, a measurement area of the subject is alternatelyirradiated with the plurality of lights generated by the first andsecond light emission elements, and a plurality of signals, generated bythe lights being reflected from the subject, may be detected atdifferent times (S201).

According to another exemplary embodiment, after the first and secondlight emission elements are alternately driven at different times for apredetermined time period during an initial stage of measurement, alight emission element having a high SNR is selected based on thedetected signals and then the measurement may be performed by drivingonly the selected light emission element, and FIG. 39 illustrates anexample thereof.

Referring to FIG. 39, the first and second light emission elements(first and second light sources) may be alternately driven at differenttimes for only a predetermined time period during an initial stage ofmeasurement, a light emission element having a high SNR is selectedbased on the detected signals and then the measurement may be performedby driving only the selected light emission element (first lightemission element).

To drive the first and second light emission elements alternately, asillustrated in FIGS. 37 to 39, the first and second light emissionelements and the light source driver connected thereto may be configuredas illustrated in FIG. 40. FIG. 40 is a circuit diagram showing anexample of a light emission portion 100D related to the method ofdetecting biological information of FIGS. 37 to 39.

Referring to FIG. 40, both of a first light emission element 10D and asecond light emission element 20D may be diodes. For example, one of thefirst and second light emission elements 10D and 20D may be an LED andthe other thereof may be an LD. In this case, the first light emissionelement 10D and the second light emission element 20D may be connectedin parallel in the opposite direction (opposite rectification direction)to a light source driver DD1. In this case, any one of the first andsecond light emission elements 10D and 20D may be driven by using thelight source driver DD1 in a direction of a current applied to the lightemission portion 100D. When the current is applied in a first directiona1, the first light emission element 10D may be driven. When the currentis applied in a second direction a2 that is opposite to the firstdirection a1, the second light emission element 20D may be driven.Accordingly, the first and second light emission elements 10D and 20Dmay be alternately driven by changing the direction of current appliedfrom the light source driver DD1 to the light emission portion 100D.Accordingly, the circuit structure of FIG. 40 may be applied toimplement the methods of FIGS. 37 to 39. However, the circuit structureof FIG. 40 is exemplary and may be changed in various ways. Also, thecircuit structure may be modified to use in conjunction with a detectionmethod.

According to another exemplary embodiment, in the operation S100 of FIG.36, the measurement area of a subject may be simultaneously irradiatedwith light from at least two light emission elements by simultaneouslydriving the at least two light emission elements. In this case, in theoperation S200 of FIG. 36, the signals may be detected by using aplurality of different light receiving devices. The method may besummarized as shown in a flowchart of FIG. 41.

Referring to FIG. 41, a method of detecting biological informationaccording to the present exemplary embodiment may include simultaneouslyirradiating to a measurement area of a subject with a plurality oflights (incident lights) having different light emission angles bysimultaneously driving at least two light emission elements (S102),detecting a plurality of signals generated by light reflected from themeasurement area by using a plurality of different light receivingdevices (S202), and selecting a signal having a high SNR from among thedetected signals and extracting and analyzing biological information ofthe subject using the selected signal (S302). In the present exemplaryembodiment, the light receiving devices in use may include, for example,the first light receiving device PD1 and the second light receivingdevice PD2 of FIG. 11. Also, the a plurality of light receiving devicemay correspond to the light receiving device regions 210 and 220described with reference to FIGS. 17 to 20.

In some cases, instead of selecting a signal having a high SNR in thethird operations S300, S301, and S302 of FIGS. 36, 37, and 41,biological information of a subject may be extracted and analyzed bycombining the detected signals.

FIG. 42 schematically illustrates a structure of a biologicalinformation detection apparatus 1500, according to another exemplaryembodiment.

Referring to FIG. 42, the biological information detection apparatus1500 may include a biological signal measurement unit M15 configured tomeasure a biological signal of the subject SBJ. The biologicalinformation detection apparatus 1500 may include a processor (processorunit) P15 comprising a data processor that extracts and analyzes thebiological information of the subject SBJ from data measured by thebiological signal measurement unit M15. The biological informationdetection apparatus 1500 may further include a driver and signalconverter DS15 that are connected to the biological signal measurementunit M15 and the processor (including the data processor) P15.

A light emission portion LT15 of the biological signal measurement unitM15 may include a light emitting unit LU15 having a variable lightemission angle. A light emission angle of the light emitting unit LU15may vary between a maximum angle θ1 and a minimum angle θ2. The maximumangle θ1 may be determined, for example, to be about 180° or less orabout 170° or less. The minimum angle θ2 may be determined, for example,to be about 0° or more or about 5° or more. The ranges of the maximumangle θ1 and the minimum angle θ2 may vary according to the type of alight source used in the light emitting unit LU15. Also, the ranges ofthe maximum angle θ1 and the minimum angle θ2 may vary according to thestructure of the light emission angle control element used in the lightemitting unit LU15. A light emission angle of the light emitting unitLU15 may be controlled according to a distance d between the lightemission portion LT15 and the subject SBJ. Illumination intensity andthe light irradiation area of an incident light L15 radiated by thelight emitting unit LU15 to the subject SBJ may be easily controlled bycontrolling the light emission angle of the light emitting unit LU15.Accordingly, optimal illumination intensity and an optimal lightirradiation area may be easily secured regardless of the distance d.

The biological signal measurement unit M15 may further include aphotodetector DT15 that detects light L15′ that is irradiated by thelight emission portion LT15 onto the subject SBJ and modulated by, forexample, reflected or scattered by the subject SBJ. The photodetectorDT15 may be arranged adjacent to the light emission portion LT15 and mayinclude at least one light receiving device. For example, a photodiode,a phototransistor, or a charge-coupled device (CCD) may be used as thelight receiving device.

Since the structure and function of each of the driver and signalconverter DS15 and the processor P15 connected to the biological signalmeasurement unit M15 may be the same as or similar to those of thedriver and signal converter DS10 and the processor P10 described withreference to FIG. 1, detailed descriptions thereof will be omitted.

In the present exemplary embodiment, the same effect as that obtained bythe light emission elements LL10 and LL20 of FIG. 1 having the differentlight emission angles θ1 and θ2 may be obtained by using the lightemitting unit LU15 having a variable light emission angle.

The light emitting unit LU15 of FIG. 42 may include a predeterminedlight source and a light emission angle control element configured tocontrol the light emission angle of the predetermined light source. Astructure of the light emitting unit LU15 is described below withreference to FIG. 43.

FIG. 43 illustrates a structure of the light emitting unit LU15 of FIG.42, according to an exemplary embodiment. Referring to FIG. 43, thelight emitting unit LU15 may include a light source LS5 and a lightemission angle control element AC5 to control a light emission angle ofthe light source LS5. The light source LS5 may be, for example, an LEDor an LD, or other light emitting source (light emitting device). Thelight emission angle control element AC5 may include, for example, avariable focusing lens. In this case, the light emission angle controlelement AC5 may include an auto focusing module (AFM) using a voice coilmotor (VCM), a liquid lens using electrowetting, or a variable focallength microlens comprising liquid crystal.

FIG. 44 is a cross-sectional view showing an example of a structure ofthe light emission angle control element AC5 of FIG. 43. In the presentexemplary embodiment, the light emission angle control element AC5 hasan AFM structure.

Referring to FIG. 44, the light emission angle control element AC5 mayinclude a housing structure 60 having an AFM structure, and a lensmodule 50 may be provided in the housing structure 60. The lens module50 may include at least one lens and a lens barrel. The lens module 50may be provided in a lens holder 52. The lens holder 52 may be a type ofbobbin. A coil 54 may surround the lens holder 52, and a magnetic member56 may be provided corresponding to the coil 54. A spring member 58 maybe provided between the lens holder 52 and the housing structure 60. Thespring member 58 may be provided at upper and lower portions of the lensholder 52. The spring member 58 may be, for example, a plate spring. Thelens module 50 may be moved up and down according to the direction ofcurrent applied to the coil 54.

The light emission angle control element AC5 of FIG. 44 may be locatedunder the light source LS5 of FIG. 43, and may be in an orientationwhich is upside-down as compared to the orientation as illustrated inFIG. 44. The AFM structure of FIG. 44 is exemplary and may be modifiedin various ways. Also, instead of the AFM structure, the light emissionangle control element AC5 may include a liquid lens using electrowettingor a variable focal length microlens using liquid crystal. Since thestructures of a liquid lens and a variable focal length microlens areknown, detailed descriptions thereof are omitted.

According to the present exemplary embodiment, a light emission portionmay include two or more light emitting units (light sources), and aphotodetector may include two or more light receiving devices. In thefollowing description, various plane structures (array structures) ofthe biological signal measurement unit are described below withreference to FIGS. 45 to 48.

FIG. 45 is a plan view showing a structure of a biological signalmeasurement unit for use with the biological information detectionapparatus, according to another exemplary embodiment.

Referring to FIG. 45, a light emission portion 150A may include a lightemitting unit 15 having variable light emission angles. The lightemitting unit 15 may correspond to the light emitting unit LU15 of FIG.42. A plurality of light receiving devices 250 may be provided aroundthe light emission portion 150A. For example, two light receivingdevices 250 may be provided at opposite sides of the light emissionportion 150A. A plurality of light receiving devices 250 may form asingle photodetector. The light emission portion 150A and the lightreceiving devices 250 are provided on a substrate 1. The substrate 1 maybe, for example, a PCB, or another type of substrate. The substrate 1may be a support.

Although FIG. 45 illustrates a case in which the two light receivingdevices 250 are provided at opposite sides of the light emission portion150A, as illustrated in FIG. 46, four light receiving devices 250 may beprovided at upper, lower, left, and right sides, respectively, of thelight emission portion 150A. In other words, one of the light receivingdevices 250 may be provided at each of at least four positions aroundthe light emission portion 150A.

In FIGS. 45 and 46, the light emission portion 150A may include aplurality of light emitting units 15. Also, the number and arrangementmethod of the light receiving devices 250 may vary. Referring to FIG.47, a light emission portion 150B may have a structure in which aplurality of light emitting units 15 are arranged in a 2D array. Also,the light receiving devices 250 may be arranged forming an annular shapearound the light emission portion 150B.

FIG. 48 is a plan view showing a structure of a biological signalmeasurement unit, according to another exemplary embodiment.

Referring to FIG. 48, a light emission portion 160 may have a structurein which a plurality of light emitting units 15 form at least one line.A plurality of light receiving devices 251 may be provided around thelight emission portion 160. The light receiving devices 251 may bearranged forming an array at at least one side of the light emissionportion 160. For example, light receiving device arrays 260 a and 260 b,each including a plurality of light receiving devices 251, may beprovided, respectively, at opposite sides of the light emission portion160, as shown in FIG. 48. Although FIG. 48 illustrates that the lightemitting units 15 of the light emission portion 160 form one line, anarray structure having two or more lines may be used.

The plane structures (array structures) described with reference toFIGS. 45 to 48 are exemplary and the structures may be modified invarious ways to the structures described with reference to FIGS. 12 to23, or structures similar thereto.

According to another exemplary embodiment, the biological signalmeasurement unit M15 of FIG. 42 may further include at least one lightemission element having a light emission angle, which is fixed on thelight emission portion LT15, and FIGS. 49 and 50 illustrate examplethereof.

Referring to FIG. 49, in a biological signal measurement unit M16, alight emission portion LT16 may include a light emitting unit LU16having variable light emission angles and a light emission element LL16having a fixed light emission angle. The light emission element LL16 maycorrespond to the first light emission element LL10 or the second lightemission element LL20 of FIG. 1, or may be similar thereto. The lightemitting unit LU16 may correspond to the light emitting unit LU15 ofFIG. 42, or may be similar thereto. The biological signal measurementunit M16 may include a photodetector DT16.

Referring to FIG. 50, in a biological signal measurement unit M17, alight emission portion LT17 may include a light emitting unit LU17having variable light emission angles and a plurality of light emissionelements LL17 and LL27 having a fixed light emission angle. The lightemission elements LL17 and LL27 may include the first light emissionelement LL17 and the second light emission element LL27. The first lightemission element LL17 and the second light emission element LL27 maycorrespond to the first light emission element LL10 and the second lightemission element LL20 of FIG. 1, respectively, or may be similarthereto. The light emitting unit LU17 may correspond to the lightemitting unit LU15 of FIG. 42, or may be similar thereto. The biologicalsignal measurement unit M17 may include a photodetector DT17.

As illustrated in FIGS. 49 and 50, when the light emitting unit LU16 orLU17 having variable light emission angle and at least one of lightemission elements LL16, LL17, and LL27 having a fixed light emissionangle are used together, the measurement may be performed while changingthe light emission angle of the light emitting units LU16 or LU17, andalso the measurement may be performed using the light emission elementsLL16, LL17, and LL27, which may be advantageous to the measurement of abiological signal in many aspects.

According to another exemplary embodiment, the biological signalmeasurement unit M15 of FIG. 42 may further include a distance measuringsensor that is adjacent to the light emission portion LT15, and FIG. 51illustrates an example thereof.

Referring to FIG. 51, a biological signal measurement unit M18 mayinclude a light emission portion LU18 and a photodetector DT18, and mayfurther include a distance measuring sensor DM18 that is adjacent to thelight emission portion LU18. The light emission portion LU18 and thephotodetector DT18 may correspond to the light emission portion LU15 andthe photodetector DT15 of FIG. 42, respectively. The light emissionportion LU18 may be a light emitting unit having a variable lightemission angle. The distance measuring sensor DM18 may be a device tomeasure a distance d of FIG. 42 between the light emission portion LU18and a subject (not shown) to be measured. The distance measuring sensorDM18 may have a structure that is the same as or similar to a proximitysensor. A distance between the light emitting unit LU18, or a lightsource included therein, and the subject may be measured using thedistance measuring sensor DM18, and a light emission angle of the lightemitting unit LU18 may be controlled according to the measured distance.The use of the distance measuring sensor DM18 is optional. The distancemeasuring sensor DM18 of FIG. 51 may be used with the biological signalmeasurement units M16 and M17 of FIGS. 49 and 50.

FIG. 52 is a block diagram showing a structure of the biologicalinformation detection apparatus 1500 of FIG. 42.

Referring to FIG. 52, a biological information detection apparatus 1500Amay include the biological signal measurement unit M15. The biologicalsignal measurement unit M15 may have the structure of the biologicalsignal measurement unit M15 described with reference to FIG. 42 or anyone of various structures modified therefrom. The biological informationdetection apparatus 1500A may include a processor (processor unit) P15having a data processor DP15 that extracts and analyzes biologicalinformation of the subject SBJ from data measured by the biologicalsignal measurement unit M15. The processor P15 may further include acontroller CL15 to control an overall operation of the biologicalinformation detection apparatus 1500A. The biological informationdetection apparatus 1500A may further include a light source driver DD15connected to the biological signal measurement unit M15. The lightsource driver DD15 may be connected to the processor P15. The biologicalinformation detection apparatus 1500A may further include a signalconverter SC15 that is connected between the biological signalmeasurement unit M15 and the processor P15. The signal converter SC15may be connected to the light source driver DD15. Although notillustrated, the processor P15 may further include a data communicationunit and/or memory. The light source driver DD15, the signal converterSC15, the controller CL15, and the data processor DP15 of FIG. 52 may besimilar to the light source driver DD10, the signal converter SC10, thecontroller CL10, and the data processor DP10 of FIG. 29. Also, in thepresent exemplary embodiment, a light emission angle of the lightemitting unit LU15 may be automatically controlled as necessary usingthe controller CL15 and the light source driver DD15.

FIG. 53 is a block diagram showing a structure of a biologicalinformation detection apparatus 1500B, according to another exemplaryembodiment.

Referring to FIG. 53, as described in FIG. 52, the biologicalinformation detection apparatus 1500B may include the biological signalmeasurement unit M15, the light source driver DD15, the signal converterSC15, and the processor P15. The biological information detectionapparatus 1500B according to the present exemplary embodiment mayfurther include an input unit IN15, an output unit OUT15, a memory MR15,and a communication unit CM15, which are connected to the processor P15.The input unit IN15, the output unit OUT15, the memory MR15, and thecommunication unit CM15 may be the same as or similar to the input unitIN10, the output unit OUT10, the memory MR10, and the communication unitCM10 described in FIG. 30, respectively. Also, the structure of FIG. 53may be changed in various ways as described with reference to FIGS. 31to 33.

In the following description, the biological information detectionmethods according to the present exemplary embodiments are describedbelow.

FIG. 54 is a flowchart explaining a method of detecting biologicalinformation, according to another exemplary embodiment. The followingdescription with reference to FIG. 54 is related to the biologicalinformation detection apparatus described with reference to FIGS. 42 to53 and relevant descriptions thereof. Accordingly, the method of FIG. 54may be understood based on the descriptions of FIGS. 42 to 53.

Referring to FIG. 54, a method of detecting biological informationaccording to the present exemplary embodiment may include irradiating ameasurement area of a subject with light from at least one lightemission element having a variable light emission angle (viewing angle)(S150), detecting a signal generated from light reflected from themeasurement area (S250), and extracting and analyzing biologicalinformation of the subject using the detected signal (S350). In theoperation S150, the at least one light emission element having avariable light emission angle (viewing angle) may correspond to, forexample, the light emitting unit LU15 of FIG. 42. The signal detectionof the operation S250 may be performed by, for example, thephotodetector DT15 of FIG. 42. The biological information extraction andanalysis of the operation S350 may be performed by, for example, thedata processor DP15 of FIGS. 42 and 52.

According to the present exemplary embodiment, in the operation S150, adistance between the light emitting unit (light source) and the subjectmay be measured and a light emission angle of the light emitting unitmay be changed according to a measured distance. The method may besummarized as shown in a flowchart of FIG. 55.

Referring to FIG. 55, a method of detecting biological informationaccording to the present exemplary embodiment may include measuring adistance between the light emitting unit (light source) and the subject(S151), changing a light emission angle of the light emitting unitaccording to the measured distance (S251), and measuring a biologicalsignal of the subject using the light emitting unit having the changed(controlled) light emission angle (S351).

In the operation S151, there may be various methods to measure thedistance between the light emitting unit (light source) and the subject.For example, when a distance between the light emitting unit (lightsource) and a skin surface of the subject is relatively long, a directcurrent (DC) level of a detected signal, for example, a pulse wavesignal, decreases. When the distance is relatively short, the DC levelof a detected signal increases. As the DC level, that is, the height ofa DC component, is analyzed using the above principle, the distancebetween the light emitting unit (light source) and the subject may becalculated. The relation between the above-described distance betweenthe light emitting unit (light source) and the subject and the DC levelof a detected signal may be represented by a graph of FIG. 56.

Referring to FIG. 56, a graph A denotes a detected signal correspondingto a case in which the distance between the light emitting unit (lightsource) and the subject is relatively long, and a graph B denotes adetected signal corresponding to a case in which the distance betweenthe light emitting unit (light source) and the subject is relativelyshort. When the distance between the light emitting unit (light source)and the subject is relatively long (graph A), a detected signal may havea relatively low DC level DC1, and when the distance is relatively short(graph B), a detected signal may have a relatively high DC level DC2.Accordingly, the distance between the light emitting unit (light source)and the subject may be calculated by measuring and analyzing the DClevel of a detected signal. Accordingly, the data processor of theprocessor P15 of FIG. 42 may further include a DC component analysisunit. Similarly, the data processor of the processor P10 of FIG. 1 mayfurther include a DC component analysis unit. However, the method ofmeasuring a distance between the light emitting unit (light source) andthe subject may be changed in various ways. As an example, asillustrated in FIG. 51, when the distance measuring sensor DM18 is inuse, the distance may be directly measured using the distance measuringsensor DM18.

As such, after the distance between the light emitting unit (lightsource) and the subject is measured, a light emission angle of the lightemitting unit (light source) is adjusted to an appropriate valueaccording to the measurement, and then, a biological signal is measuredusing the adjusted light emission angle. Accordingly, optimalillumination intensity and an optimal light irradiation area may beeasily obtained, and as a result, accuracy and reliability in themeasurement may be greatly improved.

According to another exemplary embodiment, as illustrated in FIG. 57,after a plurality of signals corresponding to a plurality of lightemission angles are detected while a light emission angle of a lightemitting unit having a variable light emission angle is changed (S152),and a signal having a high SNR is selected from among the detectedsignals and biological information of the subject may be extracted andanalyzed by using the selected signal (S252). In the method, thedistance measurement operation may be omitted and, after a plurality ofsignals are detected while freely changing a light emission angle of thelight emitting unit, a signal having a high SNR is selected from amongthe signals and used for extracting and analyzing biologicalinformation. In some cases, in the operation S252, instead of selectinga signal having a high SNR, the biological information of a subject maybe extracted and analyzed by combining detected signals.

In addition, in the biological information detection apparatus 1000 ofFIG. 1, a variety of factors (variables) may be taken into considerationin determining a range of the first light emission angle θ1 and a rangeof the second light emission angle θ2. For example, considering thedistance between the first light emission element LL10 and thephotodetector DT10, the distance between the first light emissionelement LL10 and the subject SBJ, a divergence angle of diffusereflection of the first incident light L10 on the surface (body surface)S1, and a width of an effective signal generation area of the surfaceS1, a range of the first light emission angle θ1 may be determined.Similarly, considering the distance between the second light emissionelement LL20 and the photodetector DT10, the distance between the secondlight emission element LL20 and the subject SBJ, a divergence angle ofdiffuse reflection of the second incident light L20 on the surface S1,and a width of an effective signal generation area of the surface S1,the range of the second light emission angle θ2 may be determined. Also,in the biological information detection apparatus 1500 of FIG. 42, whena light emission angle range of the light emitting unit LU15 isdetermined, a variety of factors (variables) such as the distancebetween the light emitting unit LU15 and the photodetector DT15, thedistance between the light emitting unit LU15 and the subject SBJ, adivergence angle of diffuse reflection of the incident light L15 on thesurface S1, and a width of an effective signal generation area of thesurface S1 may be taken into consideration the surface S1.

According to another exemplary embodiment, the measurement may beperformed in a state in which the biological signal measurement unitapproaches or is in contact with an effective measurement area of thesubject, and FIGS. 58 and 59 illustrate examples thereof.

FIG. 58 illustrates a case in which the measurement is performed whilethe biological signal measurement unit M10 is in contact with aneffective measurement surface of the surface S1 of the subject SBJ, asdescribed with reference to FIG. 1. FIG. 59 illustrates a case in whichthe measurement is performed while the biological signal measurementunit M15 is in contact with an effective measurement surface of thesurface S1 of the subject SBJ, as described with reference to FIG. 42.

The exemplary embodiments illustrated in FIGS. 58 and 59 may correspondto a case of detecting a photoplethysmogram (PPG) signal of the subjectSBJ. The PPG signal may be measured by using the principle that anoptical signal that is reflected or scattered varies according to achange in the volume of blood existing in a blood vessel BV2 of thesubject SBJ. Since reflection and scattering of light decreases when anamount of blood is relatively large and increases when an amount ofblood is relatively small, the PPG signal may be changed according tocontraction and relaxation of the blood vessel BV2.

When the light emission elements LL10 and LL20 having different lightemission angles are used as in FIG. 58, or the light emitting unit LU15having a variable light emission angle is used as in FIG. 59, accuracyin the measurement of a PPG signal may be improved. For example, whenskin tissues of the subject SBJ in FIG. 58 are relatively thin, thefirst light emission element LL10 having a relatively large lightemission angle is mainly used for the measurement. When the skin tissuesof the subject SBJ in FIG. 58 are relatively thick, the second lightemission element LL20 having a relatively small light emission angle ismainly used for the measurement. When the skin tissues of the subjectSBJ are relatively thick, intensity of light arriving at the bloodvessel BV2 may be decreased. Accordingly, the use of the second lightemission element LL20 having a relatively small light emission angle maybe advantageous for the measurement. Similarly, in the exemplaryembodiment of FIG. 59, when the light emission angle of the lightemitting unit LU15 is adjusted according to the thickness of the skintissues of the subject SBJ, accuracy in the measurement may be improved.Also, after a plurality of signals are detected using the light emissionelements LL10 and LL20 of FIG. 58, or while changing a light emissionangle of the light emitting unit LU15 of FIG. 59, signals having a highSNR are selected from among the detected signals and then biologicalinformation may be analyzed, or biological information may be analyzedby combining data from the signals.

It should be understood that exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments. For example, one ofordinary skill in the art to which the present inventive conceptpertains would understand that the apparatuses and systems for detectingbiological information and the methods of detecting biologicalinformation described with reference to FIGS. 1 to 59 may be changed invarious ways. For example, the light emission direction of the firstlight emission element LL10 and the light emission direction of thesecond light emission element LL20 may form a predetermined angleinstead of being parallel to each other. The photodetector DT10 may belocated at a height different from those of light emission elements LL10and LL20. The positional relationship between the photodetector DT10 andthe light emission portion LT10 may be changed in various ways. Also, ameasurement unit that detects light passing through (i.e., transmitted)a predetermined portion of a subject may be used, or a measurement unitthat detects a biological signal other than a surface pulse wave signalor a PPG signal of a subject may be used. While one or more exemplaryembodiments have been described with reference to the figures, it willbe understood by those of ordinary skill in the art that various changesin form and details may be made therein without departing from thespirit and scope as defined by the following claims.

What is claimed is:
 1. An apparatus for detecting biologicalinformation, the apparatus comprising: a biological signal measurementunit comprising a light emission portion and a photodetector andconfigured to measure a biological signal of a subject, the lightemission portion comprising at least two light emission elements havingat least two different light emission angles, respectively, wherein thephotodetector is configured to detect light generated by the lightemission portion and modulated by the subject and to generate aplurality of signals based on the detected light, and a data processorconfigured to extract and analyze the biological information of thesubject based on the plurality of signals from the biological signalmeasurement unit; a direct current (DC) component analysis unitconfigured to detect a DC level of the biological signal, wherein the atleast two light emission elements comprise a first light emissionelement and a second light emission element, the first light emissionelement having a first light emission angle smaller than a second lightemission angle of the second light emission element, and wherein thedata processor is configured to: in response to detection of a low DClevel by the DC component analysis unit, select a first signal among theplurality of signals, the first signal being generated by the biologicalsignal measurement unit based on light emitted from the first lightemission element, in response to detection of a high DC level by the DCcomponent analysis unit, select a second signal among the plurality ofsignals, the second signal being generated by the biological signalmeasurement unit based on light emitted from the second light emissionelement, and extract and analyze the biological information of thesubject by using the selected first signal or the selected secondsignal.
 2. The apparatus of claim 1, wherein the first light emissionangle is about 0° to about 90°, and the second light emission angle isabout 80° to about 180°.
 3. The apparatus of claim 1, wherein the firstlight emission element comprises a laser diode (LD), and the secondlight emission element comprises a light emitting diode (LED).
 4. Theapparatus of claim 1, wherein one of the first light emission elementand the second light emission element further comprises an opticalelement configured to adjust a light emission angle of light transmittedtherethrough.
 5. The apparatus of claim 4, wherein the optical elementcomprises at least one of a lens, an optical waveguide, a slit, aconcave mirror, and a convex mirror.
 6. The apparatus of claim 4,wherein one of the first light emission element and the second lightemission element comprises the optical element and the other of thefirst light emission element and the second light emission element doesnot comprise the optical element.
 7. The apparatus of claim 4, whereinthe first light emission element comprises a first optical element, andthe second light emission element comprises a second optical elementdifferent from the first optical element.
 8. The apparatus of claim 1,wherein the data processor is further configured to receive theplurality of signals, to select, from the plurality of signals, a signalhaving a signal-to-noise ratio (SNR) higher than that of at least oneother of the plurality of signals, and to extract and analyze thebiological information of the subject using the selected signal.
 9. Theapparatus of claim 1, wherein the photodetector comprises at least onelight receiving device configured to receive both of light output by thefirst light emission element and modulated by the subject and lightoutput by the second light emission element and modulated by thesubject.
 10. The apparatus of claim 1, wherein the photodetectorcomprises at least one first light receiving device and at least onesecond light receiving device, and the at least one first lightreceiving device is configured to selectively receive an light output bythe first light emission element and modulated by the subject, and theat least one second light receiving device is configured to selectivelyreceive light output by the second light emission element and modulatedby the subject.
 11. The apparatus of claim 10, wherein the first lightemission element generates light of a first wavelength range, and thesecond light emission element generates light of a second wavelengthrange different from the first wavelength range, and the at least onefirst light receiving device is configured to receive the light of thefirst wavelength range, and the at least one second light receivingdevice is configured to receive the light of the second wavelengthrange.
 12. The apparatus of claim 1, wherein the photodetector comprisesa plurality of light receiving devices, and the plurality of lightreceiving devices are disposed in an array surrounding at least onelight emission element of the light emission portion.
 13. The apparatusof claim 1, wherein the photodetector comprises a plurality of deviceregions arranged around the light emission portion, and each of theplurality of device regions comprises a plurality of light receivingdevices configured to receive light in different wavelength ranges,respectively.
 14. The apparatus of claim 1, wherein the light emissionportion comprises a plurality of first light emission elements, eachhaving the first light emission angle and a plurality of second lightemission elements, each having the second light emission angle, and theplurality of first light emission elements and the plurality of secondlight emission elements are arranged in a two-dimensional array.
 15. Theapparatus of claim 1, wherein: the light emission portion comprises aplurality of light emission elements and the photodetector comprises aplurality of photodetecting units, and the biological signal measurementunit comprises a plurality of sub-units, wherein each of the pluralityof sub-units comprises at least one of the plurality of light emissionelements and at least one of the plurality of photodetecting units. 16.The apparatus of claim 1, wherein the biological signal measurement unitis configured to measure an effective measurement surface of the subjectvia a non-contact method.
 17. The apparatus of claim 1, wherein thebiological signal measurement unit further comprises at least one spacerprotruding toward one side of the biological signal measurement unit,wherein the at least one spacer separates the light emission portion andthe photodetector from a surface of the subject.
 18. The apparatus ofclaim 1, wherein the biological signal measured by the biological signalmeasurement unit comprises at least one of a surface pulse wave and aphotoplethysmogram (PPG) of the subject.
 19. The apparatus of claim 1,wherein the biological information extracted and analyzed by the dataprocessor comprises at least one of a blood pressure, a heart rate, ablood oxygen saturation, a blood vessel elasticity, a blood flow rate,and arterial stiffness.
 20. The apparatus of claim 1, furthercomprising: a light source driver connected to the biological signalmeasurement unit; and a signal converter connected between thebiological signal measurement unit and the data processor.
 21. Theapparatus of claim 1, further comprising a processor, wherein theprocessor comprises the data processor and a controller.
 22. Theapparatus of claim 1, wherein at least one of the light emissionportion, the photodetector, and the data processor comprises at least aportion of one of a portable device and a wearable device.